Effects of Chilling and Defoliation on Flush Production of ACP Host Plants
Florida's orange industry has suffered more than $1.7 billion dollars in losses due to the impacts of the Asian Citrus Psyllid (ACP). This insect is a vector of a deadly disease known as Huanglongbing (HLB) (Hoddle, 2012). The disease severely affects the appearance, economic value, and productivity of the tree. Biological control of the ACP is focused on the use of parasitoids (Tamarixia radiata) to attack the ACP nymphs (Hoddle, 2012). In the laboratory, large numbers of the beneficial wasp are bred using ACP eggs as the host. ACP are left to feed and citrus plants and lay eggs, providing the resources required for T. radiata to reproduce. ACP prefer to feed on fresh, young plant growth, termed flush. Our experiment aimed to test the effects of chilling and defoliation to induce flush on three citrus varieties: Murraya koenigii, Murraya parniculata, and Citrus x volkameriana. Increased flush production on the citrus plants will improve the rate and efficacy of the biocontrol release program at UCR. Our results show significant levels of flush production in M. koenigii and M. parniculata in the early weeks of cold treatment followed by a considerable reduction of flush and vitality of those species with longer cold treatment. Citrus x volkameriana did not suffer vitality loss and produced more flush than the control in the last weeks of treatment.
This project was funded in part by The Agricultural Research Institute (ARI) program 14-04-213